[eli5] Humans and most animals breathe in O2(dioxide) and breathe out CO2(carbon dioxide) , where does the carbon come from?

Question

[eli5] Humans and most animals breathe in O2(dioxide) and breathe out CO2(carbon dioxide) , where does the carbon come from?

In: Biology

Answer 1

humans breathe o2 but they use o2 and carbohydrates for cell respiration, and the end products are co2 and water. carbs are just oxygen, carbon, and hydrogen in different amounts and arrangements.